Foetal heat production in the fowl

Romijn, C.; Lokhorst, W.

doi:10.1113/jphysiol.1960.sp006384

Cited by 76 publications

(13 citation statements)

References 7 publications

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“…These numbers correspond to an in E m wet a juvenile that is 30% dry biomass of 7,200 J/g in days 6-12 and 3,500 J/g in days 13-18. The values of E m estimated from the data in Altman and Dittmer (1968) and Romijn and Lokhorst (1960) are consistent with these values. All of these estimates indicate (i) when percentage of dry biomass is considered, E m in chick embryos is much closer to our estimates of E m in juveniles, but (ii) is about E m dry twice as high early in ontogeny versus late in ontogeny, which is where the majority of biomass increase occurs.…”

Section: A More Detailed Analysis Of E M Based On Dry Biomass In Embryossupporting

confidence: 81%

Revisiting a Model of Ontogenetic Growth: Estimating Model Parameters from Theory and Data

Moses

Hou

Woodruff

et al. 2008

The American Naturalist

134

120

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The ontogenetic growth model (OGM) of West et al. provides a general description of how metabolic energy is allocated between production of new biomass and maintenance of existing biomass during ontogeny. Here, we reexamine the OGM, make some minor modifications and corrections, and further evaluate its ability to account for empirical variation on rates of metabolism and biomass in vertebrates both during ontogeny and across species of varying adult body size. We show that the updated version of the model is internally consistent and is consistent with other predictions of metabolic scaling theory and empirical data. The OGM predicts not only the near universal sigmoidal form of growth curves but also the M(1/4) scaling of the characteristic times of ontogenetic stages in addition to the curvilinear decline in growth efficiency described by Brody. Additionally, the OGM relates the M(3/4) scaling across adults of different species to the scaling of metabolic rate across ontogeny within species. In providing a simple, quantitative description of how energy is allocated to growth, the OGM calls attention to unexplained variation, unanswered questions, and opportunities for future research.

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Section: A More Detailed Analysis Of E M Based On Dry Biomass In Embryossupporting

confidence: 81%

Revisiting a Model of Ontogenetic Growth: Estimating Model Parameters from Theory and Data

Moses

Hou

Woodruff

et al. 2008

The American Naturalist

134

120

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“…House Wren as given by Kendeigh et al (1956). The very close agreement of these figures with those of Romijn and Lokhorst (1960) on the respiratory exchange of the domestic fowl is striking. The very close agreement of these figures with those of Romijn and Lokhorst (1960) on the respiratory exchange of the domestic fowl is striking.…”

Section: Continuous Incubation (Cal/hour) = Nwhb(t E -T Na )I(l -C)supporting

confidence: 62%

“…of 0.727 involves no weight change, and values for developing embryos are close to this in the latter half of incubation when gaseous exchange is large enough to have repercussions on weight loss) (see Kendeigh, 1940;Romijn and Lokhorst, 1960;Kashkin, 1961 ). of 0.727 involves no weight change, and values for developing embryos are close to this in the latter half of incubation when gaseous exchange is large enough to have repercussions on weight loss) (see Kendeigh, 1940;Romijn and Lokhorst, 1960;Kashkin, 1961 ).…”

Section: Gaseous Factorsmentioning

confidence: 92%

Incubation

Drent¹

1975

Avian Biology

252

113

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“…At all incubation temperatures, eggshell temperature increased the most between 10 and 13 days of incubation, which is consistent with the findings of Nichelmann et al (1998) and Decuypere et al (1979) that embryo heat production increases during the second period of incubation (after D12). Romijin & Lokhorst (1960) also reported that at the beginning of incubation period evaporative heat loss is higher than the metabolic heat production, and therefore, the egg gains heat; however, during the second incubation period (D12 onwards) embryo metabolic heat production is much higher than its evaporative heat loss, thereby increasing eggshell surface temperature.…”

Section: Discussionmentioning

confidence: 98%

Effect of breeder age on eggshell thickness, surface temperature, hatchability and chick weigh

Gualhanone

Furlan

Fernandez-Alarcon³

et al. 2012

Rev. Bras. Cienc. Avic.

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Two experiments were carried out to study the effect of breeder age on incubation parameters (hatchability, eggshell thickness, egg surface temperature and chick weight). In Exp. 1, fertile eggs (30-and 60-wk-old breeders) were incubated at three different temperatures (36.8, 37.8 and 38.8 o C). Eggshell surface temperature was measured by attaching a thermocouple to the shell and data were collected in a datalogger every ten minutes. This study was conducted according to a 3 x 2 factorial design (three temperatures and two breeder ages). Data revealed that eggshell surface temperature changed according to incubation temperature, with the main increase occurring between 10 and 13 days of incubation, and that the maximum increase in eggshell surface temperature was not higher than +0.6 o C, irrespective of incubator temperature. The incubator temperature affected total incubation period and hatchability (%) at 38.8 o C, independent of breeder age. Heavier eggs resulted in heavier chicks, irrespective of incubator temperature. In Exp 2, the eggs (30-and 60-wk-old breeders) were incubated at 37.8 o C and eggs characteristics (weight, specific gravity, total hatchability and chicks weight) were evaluated according to a randomized experimental design. The data showed that breeder age affected eggshell thickness and chick weight (heavier eggs resulted in heavier chicks), but not specific gravity, eggshell surface temperature or hatchability. The findings of this study revealed that hatchability can be influenced by incubation temperature, but not by the breeder age. Breeder age can affect eggshell thickness, egg weight and eggshell surface temperature, but not specific gravity.

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Foetal heat production in the fowl

Cited by 76 publications

References 7 publications

Revisiting a Model of Ontogenetic Growth: Estimating Model Parameters from Theory and Data

Revisiting a Model of Ontogenetic Growth: Estimating Model Parameters from Theory and Data

Incubation

Effect of breeder age on eggshell thickness, surface temperature, hatchability and chick weigh

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